Ataxia-telangiectasia (A-T) is a rare autosomal recessive disorder that affects approximately 1 in 40,000 live births worldwide. It is characterized by a progressive cerebellar ataxia, telangiectasia, immunodeficiency, genomic instability, radiation sensitivity, and a markedly increased incidence of cancer, usually lymphoma or leukemia. Symptoms of A-T are typically manifested during the first few years of life with a wobbly gait. Loss of neuromuscular control is relentless and, by their teens, the children are usually confined to a wheel chair. They also have neurological swallowing problems which can lead to aspiration pneumonia and sinupulmonary infections. It has been estimated that up to 1% of the general population carries mutations in one allele of the ATM (ataxia-telangiectasia mutated) gene and ATM heterozygotes have an increased risk of developing breast cancer. The ATM gene encodes a large (369 kDa) protein, ATM, which is a member of the phosphatidyl inositol 3 kinase family of serine/threonine protein kinases. The major role of ATM appears to be in DNA damage recognition, especially of double strand DNA breaks. Cells that lack ATM are highly sensitive to ionizing radiation (IR) and are defective in the activation of multiple cell cycle checkpoints in response to IR and other DNA damaging agents. Understanding the function of ATM is of considerable importance to understanding the role of ATM in neural development and neurodegeneration, the molecular basis for increased cancer predisposition in A-T patients and ATM heterozygotes, and the molecular mechanisms that control how cells respond to radiation damage and radiomimetic chemotherapeutic drugs. A-T has also become a model for the study of mutation-targeted drugs for treating genetic diseases since hundreds of patient-derived cell lines are available, with identified mutations. Objectives of the 13th International Workshop on Ataxia-Telangiectasia and ATM meeting: The objectives of the meeting are to bring together an international group of basic and clinical researchers working on various aspects of A-T and related neurodegenerative diseases, as well as on the role of ATM in cancer, the DNA damage response, and in viral infections. Our goal is to stimulate research that will lead to better understanding and treatment of A-T. Specific areas of focus of the meeting will include the role of ATM and related proteins in the DNA damage response, the importance of chromatin and genomic instability in the activation of ATM, the role of ATM in the developing nervous system and in neurodegeneration, animal models of A-T, ATM mutations in breast and other human cancers, the epidemiology of ATM mutations, and the development of new treatments for A-T and the design of future clinical trials for A-T patients worldwide. We also hope to encourage new young investigators to both clinical and basic A-T/ATM research. PUBLIC HEALTH RELEVANCE: Specific areas of focus of the meeting will include the role of ATM and related proteins in the DNA damage response, the importance of chromatin and genomic instability in the activation of ATM, the role of ATM in the developing nervous system and in neurodegeneration, animal models of A-T, ATM mutations in breast and other human cancers, the epidemiology of ATM mutations, and the development of new treatments for A-T and the design of future clinical trials for A-T patients worldwide. We also hope to encourage new young investigators to both clinical and basic A-T/ATM research. [unreadable] [unreadable] [unreadable]